title: (1S,3S,8R,9S,11R)-10,10-Di-chloro-3,7,7,11-tetra-methyl-tetra-cyclo[6.5.0.0(1,3).0(9,11)]trideca-ne.
abstract: The title compound, C17H26Cl2, was synthesized from β-himachalene (3,5,5,9-tetra-methyl-2,4a,5,6,7,8-hexa-hydro-1H-benzo-cyclo-heptene), which was isolated from the essential oil of the Atlas cedar (Cedrus Atlantica). The asymmetric unit contains two independent mol-ecules with similar conformations. Each mol-ecule is built up from fused six- and seven-membered rings and two three-membered rings from the reaction of β-himachalene with di-chloro-carbene. In both mol-ecules, the six-membered ring has a half-chair conformation, whereas the seven-membered ring displays a boat conformation. The absolute configuration was established from anomalous dispersion effects.
authors.affiliation: Laboratoire de Chimie des Substances Naturelles, 'Unité Associé au CNRST (URAC16)', Faculté des Sciences Semlalia, BP 2390 Bd My Abdellah, 40000 Marrakech, Morocco.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Benharref
authors.forename: Najia
authors.initials: N
authors.lastname: Ourhriss
authors.forename: Lahcen
authors.initials: L
authors.lastname: El Ammari
authors.forename: Mohamed
authors.initials: M
authors.lastname: Saadi
authors.forename: Moha
authors.initials: M
authors.lastname: Berraho